Our long term goal is to identify the markers of chemical exposure in biological fluids and develop procedure(s) by which such marker(s) can be measured in the population who are exposed occupationally to chemicals and thus can be advised for possible adversed effects. In the proposed research we plan to study the effects of chemical exposure on plasma proteins in terms of their biological activity, concentration, and covalent modification. These changes will be measured using bio- and immunoassays, electrophoretic and chromatographic techniques. Covelent modification will be further characterized by peptide mapping, compositional and sequential amino acid analysis. The structure of the modified amino acid(s) will be determined by spectral techniques and further confirmed by independent synthesis. Benzene, ethylenechloride and ethylene oxide will be used as model compounds. Although the proposed project is limited to rats and in vitro studies with human plasma, these experiments could be extended to monitor occupationally exposed population to these or other chemicals. Correlation between the changes in plasma proteins and the medical histories of the exposed individuals can eventually be used to medical surveillance.